This invention relates to a door assembly movably mounted on a vacuum deposition apparatus for selectively closing a vacuum chamber thereof and a method for loading and unloading such chamber with articles to be processed.
Apparatus of this type comprise a plurality of racks mounted in the vacuum chamber to retain a plurality of articles or substrates, such as silicon wafers, thereon. During the deposition process, the chamber is closed and the articles are subjected to a vaporized material, such as metal. U.S. Pat. No. 3,643,625, assigned to the assignee of this application and having common inventorship, discloses an apparatus for closing and sealing the vacuum chamber during the deposition process.
In particular, a glass bell jar is mounted on the apparatus to define the vacuum chamber therein. Mounting of the jar on the apparatus and removal therefrom upon completion of the process is obviously cumbersome and unduly time-consuming. In addition, the jar must be precisely placed on the apparatus to insure a positive static seal whereby a vacuum may be effectively drawn within the jar.
Another type of deposition apparatus comprises a split vessel having the two components thereof hingedly connected together by vertically disposed hinges. The latter arrangement also gives rise to sealing problems, requires an undue amount of space for opening purposes and hinders the operator in his free access to the vacuum chamber and to a control panel mounted adjacent to the vessel when it is opened. Similar problems are encountered with other types of deposition apparatus which have an openable door mounted thereon.
For example, one type of door opens upwardly which gives rise to the additional problem of operator safety should the door inadvertently fall towards a closed position. In another type of door arrangement, the door pivots sideways to open in a sideways direction and is moved downwardly. As suggested above, all of these types of doors exhibit the above sealing, space, operator hinderance and safety problems.